Bird-sonality: What Can Lateral Preferences Tell us About Behavior?

by Kelly Welsh '05 (M.A.)

Psychologist Matthew Anderson, Ph.D., admits that sheer fascination with radiant flamingos first brought him to study the birds. But through the years, his studies have revealed many practical and important findings. His research on the iconic bird has been published in several peer-reviewed journals. He is one of a few psychologists around the world who has studied flamingos, seeking answers to questions such as, “Why do flamingos stand on one leg?” and “Do the ways in which they rest their necks say something about aggression?”

Because flamingos live in remote and inhospitable places in the wild and are characteristically shy, they have historically been very difficult to study — and many basic questions about their behavior have remained unanswered.

For Anderson, who also directs the University’s animal studies program, the Philadelphia Zoo’s 17 Caribbean flamingos have been the subjects of most of his research over the last six years. In fact, it was a study of this population performed by Anderson and two SJU seniors that yielded a first in the flamingo field back in 2009. The team discovered that, when resting, Caribbean flamingos have a personal preference for curving their necks in one direction over the other. The research was published in the journal Laterality: Asymmetries of Body, Brain and Cognition, and went on to inform most of Anderson’s work.

“Consistent lateral preferences can provide us insight into which hemisphere of the brain is more dominant in particular situations,” says Anderson. “And the fact that most Caribbean flamingos rest with their necks curved to the right most of the time indicates that this is the norm and suggests a left hemisphere dominance. So we wondered, why does this population-level lateral preference exist, and what else might be different about the behaviors of left-leaners?”

After close observation in two separate studies, it was determined that Caribbean flamingos who curve their necks to the left are generally involved in more aggressive interactions with other members of the flock than those who prefer to neck-rest to the right (Anderson, Williams, & Bono, 2010). Individual flamingos who are more strongly pair-bonded are more likely to have similar lateral neck-resting preferences to their partners than birds that are less strongly pair-bonded (Williams & Anderson, 2012).

Anderson’s findings were intriguing and he wanted to take his research a step further. Collaborating with Philadelphia Zoo veterinarian Donna Ialeggio, D.V.M., he examined how laterality might be related to various physiological health measures. Using behavioral preferences and data collected from annual blood samples, they surmised that Caribbean flamingos who prefer to rest their necks to the right are generally healthier and less stressed than those who prefer the left.

“All of this research combined paints a compelling picture of how lateral behavior and hemispheric dominance in the brain may be related to social cohesion and can be used to make predictions about other aspects of behavior,” Anderson explains. “Given the typical contralateral control of behavior in the brain, and since the left hemisphere is thought to play a role in pro-social behavior, it makes sense that flamingos with a rightward neck-resting preference seem to be healthier and get along better with other members of their flock.”

Anderson has also used an online flamingo webcam from the Smithsonian National Zoological Park and online weather data obtained from weather.com to examine the relationship between weather variables and the occurrence of aggressive behavior, discovering that temperature and UV-index were both positively related to the occurrence of aggression.

Next up are studies looking at whether social hierarchies form in captive Caribbean flamingo flocks and how they may relate to an individual flamingo’s health and well-being, and if forms of environmental enrichment (sprinklers, enrichment balls, etc.) affect behavior in captive flamingos.

“Understanding how behaviors might predict personality, health and well-being can give zookeepers important tools,” argues Anderson. “My research shows that we can learn things about these birds as a species and as individuals that could positively impact husbandry. We can use this information to make predictions about the health and level of social cohesion of the flock, and to possibly help identify compatible mates.”